I think the closest that this has come is in the form of GitLab, which pretty famously did a ton of the corporate work in the format of a very open Handbook (https://handbook.gitlab.com/)
In the early years, it was extremely, extremely open and comprehensive. I've definitely looked through it when I wasn't sure how to handle something at work.
That's pretty cool. Wonder if it is deployed and updated religiously still. If they wanted to deploy an 'Agent' worker that source is goldmine for context.
And that site is available as a git repository - on Gitlab of course:
https://gitlab.com/gitlab-com/content-sites/handbook